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Hassan Youssef, a 40-year-old victim of the April 4 chemical attack in Khan Shaykun, receives medical care in a hospital in the nearby Syrian city of Idlib in April.
Omar Haj Kadour/AFP/Getty Images
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Doctors at a hospital in Aleppo, Syria, treat a boy injured in what the government said was a chemical weapons attack on March 19. Syria's government and rebels accused each other of firing a rocket loaded with chemical agents outside of Aleppo.
George Ourfalian/Reuters/Landov
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